1. Field of the Invention
The present invention relates to teat cup inflations used in teat cup assemblies for milking cows. In particular, the invention relates to an inflation that is a one-piece, molded, elastomeric member having a hollow elongate barrel that has a substantially triangular cross-sectional shape.
2. Description of Related Art Including Information Disclosed Under 37 CFR 197 and 198
There has been much effort made in the past to provide improved teat cup inflations that massage the teats of a cow and otherwise are designed to be less likely to cause mastitis in the teats of the cows being milked. Attention is directed to U.S. Pat. Nos. 3,659,558 and 3,967,587 wherein there is generally specified the inadequacies of the prior art inflations, particularly as to undesirable conditions imposed on the teats of a cow by inflations of the prior art.
An improved inflation is disclosed in U.S. Pat. No. 3,967,587 in which the barrel of the inflation has a substantially square cross-sectional shape. At the upper or proximate end of the barrel there is a cylindrical head molded integrally to the barrel. The head has a reversely extending flange that fits over the upper end of the shell of the teat cup assembly. A mouthpart or diaphragm is provided at the upper end of the cylindrical head, with the mouthpart having a central opening for receiving the teat of a cow.
The square-shaped inflation was a significant advancement in the art and was used widely by dairies. However, current demands on the management aspects of dairying have resulted in drastically increased milk production as well as improved man-hour efficiencies. The increase in milk production has put greater demands on physiological systems of the dairy cow, milking systems and the design of milking inflations. This puts additional demands on the capacity of milking components, since a milking system that is experiencing excessive fluid flow, increases instability that ultimately can result in an undesirable decrease in milkout performance. It would be highly advantageous to develop alternative inflations having a different cross-sectional shape that would achieve or surpass the performance of the square-shaped inflation of the prior art to meet the demands of the present dairy industry.
In U.S. Pat. No. 5,482,004, issued on Jan. 9, 1996, teat cup liners, i.e., inflations, are disclosed which are especially designed to provide a differential resistance to inward collapse along the length of the teat receiving region of the barrel of the inflations. The purpose being to allow the inflations to accommodate teats of varying lengths. According to the teaching of U.S. Pat. No. 5,482,004, means are provided for creating a differential resistance to inward collapse of the teat receiving region along the length of the teat receiving region. One embodiment of such means which is disclosed in U.S. Pat. No. 5,482,004 consists of a plurality of axially extending, circumferentially spaced ribs having a maximum width and a maximum thickness at the uppermost end of the inflation, with both the width and the thickness decreasing or becoming smaller along the length of the rib. There is no suggestion whatsoever or any motivation whatsoever given in U.S. Pat. No. 5,483,004 of ribs having constant or uniform width and/or thickness in the teat receiving region of the barrel, nor is there any suggestion or motivation whatsoever that ribs of constant or uniform width and/or thickness in the teat receiving region of a triangular-shaped inflation would result in any benefit of any kind, let alone the unexpected results achieved in accordance with the present invention.
In U.S. Pat. No. 6,776,120, issued Aug. 17, 2004, round teat cup liners, i.e., inflations having a circular cross-sectional shape, are disclosed in which one of three elements are required. First, the thickness of the barrel of the inflation must decrease in size in a direction from the upper end of the inflation to the lower end. Second, elongate ribs are formed in the outer surface of the barrel of the inflation, and the elongate ribs have a thickness extending outwardly from the barrel, with the thickness increasing in size in a direction from the upper end of the inflation to the lower end. Third, that both the elements mentioned in the previous two sentences are present. There is absolutely no suggestion of ribs which are uniform in their thickness, instead, the ribs must increase in their thickness. Further, there is no suggestion of using the ribs on a triangular-shaped inflation, the inflations have a circular cross-section in the teat receiving portion of the barrel. There is no suggestion or any motivation whatsoever given in U.S. Pat. No. 6,776,120 of ribs having constant or uniform thickness in the teat receiving region of the barrel, nor is there any suggestion or motivation whatsoever that ribs of constant or uniform thickness in the teat receiving region of a triangular-shaped inflation would result in any benefit of any kind, let alone the unexpected results achieved in accordance with the present invention.